According to a regulation from the Civil Aviation Administration of China, any civil unmanned aerial vehicle (UAV) with a takeoff weight over 250 grams has to be registered before use from June 1. The rule was introduced after an airport in Chongqing was disrupted by UAVs for four hours in May, delaying more than 60 flights. Official statistics showed that in May alone, there were at least 19 reported incidents of civil flights being disturbed by UAVs. According to iResearch, a private consultancy, the market size of civilian UAVs in China stood at 2.3 billion yuan (US$344 million) in 2015 and the market is expected to reach 5.4 billion yuan (US$808 million) in 2017. The low cost and user-friendliness of UAVs have meant such flights have become prevalent, including in no-fly zones. Insiders had warned that the main challenge was the lack of a single supervisory authority, and thus the first step was to unveil the real-name registration system before eventually coming up with a complete management system for the use of UAVs.